<html>
	<head>
<title>Projeto de um site</title>
<style> 
#topo {width:100%;height:150px;
     background-color:#bff683;}         
#topocentro {width:900px;height:150px;background-color:#72b729;margin:0 auto;}

</style>
	</head>
	
	<body>
<div id="topo">

<div id="topocentro"></div>


</div>




	</body>
</html>